Improve the multi runtime editor support on touch screens

[davetcc]

The present touch screen implementation for multi runtime editors is somewhat lacking. Just showing a slider for even text fields.

This issue is to implement a very basic software matrix keyboard for such items, that initially would target anything that than be edited with a purely numeric keypad. The current matrix keyboard support should be shared with this, so that they both use the same logic for editing, as the current matrix keyboard support is quite acceptable (although could be improved slightly itself).

[davetcc]

Create a TouchButton class that can be used to generally handle touch input as part of this, replace all the hard coded logic in the calibrator UI and further use the same class to handle the cases above.